Extensive studies of breast cancer, including immunoperoxidase studies in our own laboratory, have attempted to correlate expression of hormone receptors and tumor-associated antigens with selection of therapy and eventual clinical outcome. By comparison, studies of cervical and endometrial cancer are few and far between. The majority of correlative marker studies of gynecological neoplasms have measured either serum factors or tissue homogenate antigens, thereby precluding direct correlation between cell staining patterns and standard morphologic criteria used in the diagnosis of malignancy. Immunoperoxidase techniques applied to fixed embedded tissues offer the prospect of direct visualization of antigens in standard histologic sections, and so offer the diagnostic pathologist the opportunity of simultaneously identifying normal and neoplastic cells both by their morphologic characteristics and by their antigenic constitution. The aim of the proposed study is twofold. First, we plan to extend the current peliminary immunoperoxidase study of steroid hormone receptors in gynecologic neoplasms to 50 cases each of endometrial and cervical carcinoma. The pattern and intensity of tumor cell staining for estrogen receptor, as determined by immunohistochemical methods in a retrospective study will be compared with histologic findings and the clinical outcome of the disease. In the second phase of the proposed program, the study will be broadened to include examination of the same case population for other possible tumor markers (e.g, carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), pregnancy-specific beta1 glycoprotein, lactoferrin, alpha fetoprotein, T-antigen); the potential diagnostic and prognostic significance of the interrelationships between these potential markers and the hormone receptors will be investigated. We anticipate that the combined immunohistochemical approach will lead to more precise diagnosis, to more effective discrimination between benign hyperplastic conditions and neoplasia, and to more effective selection of therapy.